A suicide bomber killed at least 37 people when he rammed his explosives-laden minibus into a crowd of recruits outside a Yemeni police academy.

The Associated Press reports the incident occurred in Sanaa, Yemen's capital where violence has soared since Shiite rebels swept down from their northern strongholds last year. The attacker struck as cadets were lined up outside the school, preparing to enroll, witnesses said. At the scene, the dead and wounded lay on a sidewalk against a wall as firefighters tried to extinguish the blaze from the vehicle's explosion.

Beyond the fatalities, dozens were wounded in the attack, the official Yemeni news agency Saba said based on government sources.

Police Brig. Gen. Abdulaziz al-Qudsi confirmed that 37 people had been killed and put the number of injured at 66. An unnamed security official noted that at least three civilians were among the dead.

No one has yet claimed responsibility for the bombing, but AP noted that Yemen's local al-Qaida branch has carried out similar assaults in the past.

The United Nations and the United States condemned the attack and expressed sympathy to the victims and their families. The U.S. government reportedly considers al-Qaida's Yemeni affiliate, which has been linked to several failed attacks in the United States, to be the most dangerous branch of the global terror network.

Yemen's interior ministry said registration at the police academy would be suspended for a week, Agence France-Presse reports. Many of the potential recruits had traveled from other parts of the country, and officials said they would try to register cadets locally in the future to prevent similar attacks.

Instability has been on the rise in Yemen ever since dictator Ali Abdullah Saleh was toppled from power in 2012, AFP explained. Shiite rebels known as the Huthis overran Sanaa unopposed on Sept. 21; they have since expanded their presence in the central and western parts of the country and have met fierce resistance from Sunni tribes and Al-Qaida militants.